Cellular reactions and bone apposition to titanium surfaces with differentsurface roughness and oxide thickness cleaned by oxidation

Titanium surfaces with three different surface characteristics were exposed to an intraperitoneal milieu in mouse or rat, or inserted into rabbit bone . The cleaning regimen of the TiO2 surfaces in this study included oxidatio n by heat or acid and a final rinsing and storage in water. Intraperitoneal exposure ranged from 1 to 64 min and the healing period in bone was 6 week s. Cell recruitment to the surfaces was quantified by acridine orange stain ing and specific antibodies directed against cell membrane antigens. Remova l torque, bone-to-metal contact, total bone area and histological evaluatio ns were used to evaluate fixture stability and the healing-in of the implan ts. After the healing period of 6 weeks only a transient significant differ ence was seen in the total number of cells adherent on the surfaces. No sig nificant differences were observed between any of the surfaces for removal torque, bone-to-metal contact, or bone area. The areas lacking bone-to-meta l contact were filled with normal vascularised connective tissue with no si gns of fibrous capsule formation or giant cells. These findings differ from findings published earlier of Ti implants that underwent a cleaning regime n with alcohol as the final rinsing step. The tissues around the implants w ere richly vascularised and there was continued bone growth toward the surf aces. The bone-to-metal contact in this study was lower than that seen with alcohol-cleaned TiO2. (C) 2001 Elsevier Science Ltd. All rights reserved.